Abstract: An improved lead for electrically stimulating muscle tissue particularly configured for a cardiac assist system powered by surgically modified skeletal muscle tissue. The skeletal muscle is either wrapped about the heart itself, or about an auxiliary pumping chamber attached to the aorta. Electrical stimulation is supplied via the improved lead to cause contraction of the skeletal muscle in synchronism with the natural or artificially paced heart rate and timed to obtain the desired hemodynamic effect. The improved lead has an electrode which is embedded in the skeletal muscle. The stimulation threshold of the skeletal muscle is held relatively low by the action of a glucocorticosteroid imbedded within the suture material. By placing the drug material in this position, it acts as an anti-inflammatory along the entire path of the suture material and treats the specific area of the electrode contact from within the muscle itself.

Abstract: This invention relates to corporeal catheters. More particularly, this invention relates to an outer exchange catheter system comprising an outer catheter sheath and at least one inner catheter having a control means, the outer catheter sheath extending less than the full length of each inner catheter and being slidable thereover. This invention also relates to the method of using this outer exchange catheter system.

Abstract: This invention relates to steerable catheters. More particularly, this invention relates to a steerable catheter comprising a flexible catheter member having distal and proximal ends and one or more lumens, the single lumen or one of the lumens being closed at its distal end, the one or more other lumens being open, for introduction of a central guide wire or other desired object; a deflection wire having distal and proximal ends and axially extending the length of the catheter member through the lumen having the closed end, the distal end of the deflection wire being embedded in the closed end; and control means attached to the proximal end of the catheter member, the proximal end of the deflection wire extending to the control means and the control means having an engaging means which fixedly engages the deflection wire.

Abstract: This invention relates to corporeal catheters. More particularly, this invention relates to an outer exchange catheter system comprising an outer catheter sheath and at least one steerable inner catheter having a control means, said outer catheter sheath extending less than the full length of each said inner catheter and being slidable thereover.

Abstract: This invention relates to steerable thru-lumen catheters and a method of using same, especially in the cardiovascular field.

Abstract: An ionic substance is mixed with a polar, non-ionic adhesive to form an electrode for use in the iontophoretic introduction of the ionic substance into a body. The electrode may be formed as a sheet of the mixture of a size and shape suitable for attachment to the electrode plate of an iontophoretic current generator. The mixture may be incorporated in an electrode as a means for holding the ionic substance, a means for attaching the electrode to the body, a means for attaching the iontophoretic current generator to the body, or a means for conducting the ionic current into the body. The electrode may also be employed in combination with an electrical stimulator to provide for simultaneous electrical stimulation and iontophoretic drug administration to the body.

Abstract: An epicardial defibrillation electrode employing an elongated, coil electrode embedded in the surface of a flexible electrode pad. The coil electrode provides increased flexibility and superior electrode flex life. The arrangement of the coil electrode provides uniform current distribution. The electrode takes the form of a space wound coil following a tortuous path over the surface of the electrode pad to provide a large surface area to reduce current density. In some embodiments, an insulative core is located within the lumen of the coil.

Abstract: A plastic stent for a prosthetic trileaflet heart valve consisting of a cylindrical body portion terminating at one end in three apical, spaced commissure posts, and at the other end, in a skirt comprising three arcuate extensions, each extension being provided with an interrupted channel adjacent the outer edge thereof. An optional metal ring may be mounted over the skirt adjacent the body portion. A cloth cover is secured to the stent by stitching directly through the skirt in the area of reduced thickness resulting from the interrupted channel.

Abstract: A heart pacemaker including a two wave length reflectance oximeter for determining oxygen saturation. The pacing rate is increased or decreased in response to the measured oxygen saturation. By appropriate multiplexing and timing functions, the two wave length reflectance oximeter is included in a pacing lead coupled to the pacemaker which requires only three conductors.

Abstract: A muscle-powered pump to assist the natural heart is disclosed. The device comprises an oblate, spheroidal-shaped pumping chamber surrounded by innervated muscular tissue. The device may be coupled to the ventricle and descending aorta with valves and be stimulated in synchrony with the natural depolarization of the heart or the device may be inserted into the descending aorta and used as a counter pulsation device. In this application, the innervated muscle is stimulated after a brief delay from the natural cardiac depolarization.

Abstract: A heart pacemaker including a two wave length reflectance oximeter for determining oxygen saturation. The pacing rate is increased or decreased in response to the measured oxygen saturation. By appropriate multiplexing and timing functions, the two wave length reflectance oximeter is included in a pacing lead coupled to the pacemaker which requires only three conductors.

Abstract: An improved heart valve having an annular valve housing and two leaflets supported for pivotable movement within the annular valve housing. Each leaflet is pivoted about an axis displaced from the center of the valve housing. When open, the leaflets pivot away from the center of the valve housing allowing for central flow. The valve leaflets are provided with curved indentations with engage curved projections from the valve housing which serve both to retain the valve leaflets within the housing and to define and control their pivotal movement during opening and closing.

Abstract: A cardioversion and defibrillation lead system and a method of use of the lead system for applying energy to the heart. The lead system and method of application are designed to maximize the efficiency of electrical energy and depolarizing the cells of the heart by equalizing current distribution across the heart and concentrating current in the muscular areas of the heart. The method of use of the lead system includes properly locating the electrodes, and applying pulses to the electrodes in one of several pulse regimes.

Abstract: A casing for a tissue stimulator includes a box portion for containing the stimulator circuitry and a cover hingeably mounted on the box portion. The cover has a clip for mounting on the user's belt. The box rotates away from the cover approximately 90.degree. to a generally horizontal position wherein the user can manipulate controls on the stimulator.

Abstract: Apparatus and method for sensing the probable onset of ventricular fibrillation or other harmful tachyarrhythmias and delivering electrical cardioverting stimulation pulses in response thereto. The sensing of the onset of the harmful tachyarrhythmia is accomplished using two different types of sensors. The first sensing technique utilizes an intracardiac ECG observed within three dimensional space. Directional changes of the current vector within the intracardiac ECG are used to predict the onset of harmful ventricular tachyarrhythmias. The second sensing technique employs a chemically sensitive semiconductor device which measures the level of ionic potassium found within the intracardiac blood. Rapid changes in ionic potassium level are used to predict the onset of detrimental ventricular tachyarrhythmias. An implantable device uses both types of sensors in a programmable fashion to deliver cardioverting electrical stimulation pulses based upon the predicted onset of ventricular fibrillation.

Abstract: A demand pacemaker which regulates its pacing rate based upon sensed oxygen saturation percentage. The pacemaker employs a two wavelength reflectance oximeter as a sensor. The sensor includes an oscillator which sequentially activates red and infrared diodes. The duty cycle of the oscillator is regulated by the relative amounts of red and infrared light reflected by the blood. The construction of the sensor allows the sensor to operate with only two conductors, optimizing it for incorporation in a standard, bipolar pacing lead.

Abstract: Apparatus and method for sensing the probable onset of ventricular fibrillation or other harmful tachyarrythmias and delivering electrical cardioverting stimulation pulses in response thereto. The sensing of the onset of the harmful tachyarrhythmia is accomplished using two different types of sensors. The first sensing technique utilizes an intracardiac ECG observed within three dimensional space. Directional changes of the current vector within the intracardiac ECG are used to predict the onset of harmful ventricular tachyarrhythmias. The second sensing technique employs a chemically sensitive semiconductor device which measures the level of ionic potassium found within the intracardiac blood. Rapid changes in ionic potassium level are used to predict the onset of detrimental ventricular tachyarrhythmias. An implantable device uses both types of sensors in a programmable fashion to deliver cardioverting electrical stimulation pulses based upon the predicted onset of ventricular fibrillation.

Abstract: Improved methods of ionophoretic drug delivery are described. By the intentional selection of drug(s) with specific characteristics, of ionotophoresis device, components or both permits the efficiency of drug delivery is increased.

Abstract: Improved iontophoresis drug delivery apparatus or device wherein one or more electrochemically active components are employed or "sacrificed" so as to minimize the hydrolysis of water during drug delivery. Efficiency of drug delivery is increased and pH changes in the device or adjacent the patient's skin are minimized.

Abstract: An improved iontophoretic device for introducing an ionic substance into body tissue. A compact casing contains all the electronic circuitry necessary for generation and control of an iontrophoretic current. Stainless steel electrode plates are mounted directly on the casing and are electrically coupled to the electronics within. The device may be used in a simplified iontophoretic procedure: adhesive pads containing the ionic substance to be driven into the body tissue are applied to the stainless steel plates and the entire iontophoretic device is then affixed to the body by the adhesive pads and a safety strap, thus permitting normal patient movement during the iontophoretic process.